/* main-nav区域 */
/* 大结构定位、宽高 */
.content .main-nav {
    position: relative;
    width: 100%;
    height: 480px;
}
/* 图片列表定位、默认隐藏 */
.content .main-nav .images li {
    display: none;
    position: absolute;
    top: 0;
    right: 0;
}
/* 显示图片 */
.content .main-nav .images li.show {
    display: block;
}
/* 左侧分类列表定位、宽高、背景、文字属性 */
.content .main-nav .list {
    position: absolute;
    top: 0;
    left: 0;
    width: 244px;
    height: 456px;
    padding: 12px 0;
    background: rgba(255, 255, 255, 0.4);
    line-height: 57px;
    color: #3a3a3a;
}
/* 边距 */
.content .main-nav .list li {
    padding-left: 30px;
} 
/* 鼠标划入高亮 */
.content .main-nav .list li:hover {
    background: rgba(255, 255, 255, 0.5);
}
/* 左右两按钮定位、宽高、背景、旋转 */
.content .main-nav .btn {
    position: absolute;
    top: 50%;
    width: 16px;
    height: 9px;
    background: url(../images/gotop-arrow.png);
    background-size: 16px 9px;
}
/* 按钮鼠标划入放大效果 */
.content .main-nav .btn-l:hover {
    transform: rotate(-90deg) scale(1.5,1.5);
}
.content .main-nav .btn-r:hover {
    transform: rotate(90deg) scale(1.5,1.5);
}
/* 按钮定位，默认旋转 */
.content .main-nav .btn-l {
    left: 254px;
    transform: rotate(-90deg);
}
.content .main-nav .btn-r {
    right: 9px;
    transform: rotate(90deg);
}
/* 小标签定位、宽高 */
.content .main-nav ol {
    position: absolute;
    bottom: 10px;
    left: 50%;
    width: 110px;
}
/* 小标签浮动、背景、边框 */
.content .main-nav ol li {
    float: left;
    width: 10px;
    height: 10px;
    border: 1px solid #c0c0c0;
    border-radius: 50%;
    margin-right: 10px;
}
/* 选中样式 */
.content .main-nav ol li.now {
    width: 11px;
    height: 11px;
    border: 0;
    background: #00c3f5;
}